An image forming apparatus using an electrophotographic developing method forms an image on a recording medium such as paper through an image forming process including charging, exposing, developing, transferring, and fixing. For example, the image forming apparatus forms a toner image on a recording medium through charging, exposing, developing, and transferring while a photoconductor rotates when a charging roller, a developing roller, a transfer roller, etc. are at predetermined positions, temperatures, and pressures applied to the toner image, and fixes the toner image on the recording medium.
A developing unit may include a developing roller which receives a toner (a developer) and supplies the toner to an electrostatic latent image formed on a photoconductor. A developing cartridge is an assembly of parts for forming a visible toner image. The developing cartridge is detachable from a main body of the image forming apparatus and is a consumable item that can be replaced when the life span thereof has ended. In the case of a developing cartridge employing a contact developing method, a developing roller and the photoconductor come into contact with each other to form a development nip. When the photoconductor and the developing roller form a development nip for a long time, there is a risk of deformation of the developing roller and damage of the photoconductor.